Method of making metal foil pans



Feb. 23,. 1954 Yw G, SWA/FN; 2,669,914

METHOD `oF MAKING METAL- FOIL PANS Filed June 12, 195o v j 2 sheets-sheet 1 FIG. 6. /lffmwff i Feb.. 23, 1954 w. G. swAxNE 2,669,914

METHOD OF MAKING METAL FOIL PANS Filed June l2, 1950 2 Sheets-Sheet 2 uw www. VM l WNV www wm P f MM, .I J I| v \L MRS:

hq mma JNVENTOR. WILLIAM G. SwAnNE BY /W# h1/#M ,47m/Wm Patented Feb. 23, 1954 METHOD F MAKING METAL FOIL PAN S William G. Swaine, Brentwood, Mo., assgnor to Aluminum Foil Packaging Co., St. Louis, Mo., a corporation of Missouri Application June 12, 1950, Serial No. 167,636

3 Claims.

This invention relates to the manufacture of baking pans from thin sheet metal, such as aluminum in thicknesses of .008 inch or less, commonly known as foil; and, more particularly, relates to single-use pans of such inexpensive construction that commercial bakeries may bake in them and distribute the baked goods without removing them from such pans.

A prime object of my invention is to devise an inexpensive pan, and a method of manufacturing same, wherein bakery goods may be partially baked at a commercial bakery, marketed without removing said pan, and finish-baked and served by the housewife in said pan.

It is another object of the present invention to produce from foil a baking pan having low cost and attractive appearance so as to be suitable as a pan and baking tray for packaging and distributing bakery goods.

A further object is to produce a foil pan possessing sufficient strength and rigidity to Withstand handling in commercial bakeries and the forces encountered in packaging, distribution, and selling.

Another object is to produce out of light sheet metal a pan having rounded corners and iianged edges interlocked with said corners.

A further object is to devise a method of manufacturing a baking pan of the type aforementioned in a single operation by a single stroke of a fast-acting machine tool, such as a punch press.

The above and other objects will become more fully apparent from the following specification, which, by way of illustration rather than limitation, sets forth a preferred process and a preferred form of pan constituting embodiments of the present invention, which is further illustrated in the accompanying drawings and, more particularly, pointed out in the claims.

In the accompanying drawings (two sheets):

Figure 1 is a perspective view of a flat foil blank from which the pan is formed;

Figure 2 is a perspective view of such blank at the next stage in the process, with the pan corner tucks initially folded upwardly;

Figure 3 is a perspective view of the next stage of forming of the pan, showing the sides folded upwardly and the corner tucks about closed;

. Figure 4 is a perspective view of a completed Dan;

Figure 5 is an enlarged fragmentary perspective detail showing a pan corner from outside and below;

, Fgure is a .plan vievr of a-Hlower or female 2 die which, with a mating die, not shown, is utilized for blanking and forming such pan in-.a double-acting punch press;

Figure 7 is a sectional view taken along line 'I-l of Figure 6;

Figure 8 is a sectional elevational View of the lower die assembly as seen at line 8--8 in Fig. 6, together with the press operated upper die parts shown in position for blanking, that is, at the stage of operation corresponding with the stage of manufacture shown in Figure 1;

Figure 9 is a similar view to Figure 8 but showing the upper die elements of Figure 8 at the pan forming stage corresponding to Figure 2;

Figure 10 is a similar view to Fig. 8 showing the die elements of Figure 8 at the forming stage vcorresponding to Figure 3; and

Figure 11 is a similar view to Fig. 8 showing the die elements of Figure 8 at the forming stage corresponding to Figure 4.

Referring now in more detail and by reference characters to the drawings', which illustrate a preferred embodiment of the present invention, the initial forming step is to produce a blank 2| of thin sheet metal; for example, aluminum foil .004 inch thick. Said blank 2l is illustrated in Figure 1 in its flat condition, that is, after blanking but before the forming operation described hereinafter.

The next step in forming is to bend up the fan-shaped rounded or arcuately iiattened corners 22 of the flat blank 2 I, as illustrated in Figure 2 and in the die of Fig. 6. Thereafter, successive operations are carried on so that the sides 23 are formed upward and outside of corners 22; and the material between said unfolded sides 23 and the corners 22 is folded upon itself at each side of the corners to form corner tucks 2s. The provision of two tucks at each corner reduces the bulk of the tucks and allows the forming of a smooth corner wall right down to the bottom surface of the pan. Further, the tucks are not formed in a haphazard manner but are located in the manner shown by the provision of separate corner die parts which have an initial forming function on the blank. As a final step, the edges of the upfolded sides 23 are bent or rolled outward and slightly downward to comprise side flanges 25. This bending operation also serves to bend outward a portion of the upper edges of tucks 24, forming a plica or nip 26. Afunction of said plica 26is to bind the material 'of corner tucks 24 to side iianges 25 and thus prevent the opening of said tucks 24 under hoop-tension loads, such as result when the pans are filled with 3 a uid or semi-fluid mass. A further function of said plicas 25 is to provide smooth, folded-over end portions for side anges 25 lessening the possibility of cutting the ngers of persons handling the pans.

The shape of blank 2| is economical in that there is little waste when suchy blanks are cut from acotinuousf 'strip of material. Plica 2 6, which resul-ts from folding and tucking blank 2l in the manner indicated, takes the place of material-wasting tabs, such as are frequently employed to secure other types Qi-sheet-fmetal In addition to the pan so described, my invention goes to the method andA process ofv manufacture of such pan. For this purpose, Iusev a con- 'ventional double-acting punch press, not shown.

The press is of known type. characterised, by a lower bed, an inner ram linked by a connecting rod to the crank-shaft o f the press, and an outer ram adapted to reciprocate along the same line of movement as. said inner.. ram VWith said type of; press, the. stroke. of the. outer-:Aram is caused to vary from coincidence. with that of5 the inner ranrby cam means. amxedf to. the crank-shaft of the press. The pressure of said. cam means is resisted by restoringv springs acting between the said inner A andV outer rams.

The.l pari above. describedy is made during a single` stroke. ot such` doubleracting punchA` press in the. manner hereinafter described and utilizes dies as shown inthedrawings and explained hereafter.

Referring. to. Figures. 6` and 8, I provide a rectangular base. plate. 211: for mounting the. lower die. assembly tothebed, ot the punch. press, (the pressitseli is oi standard constructionand isnot here illustrated). On base plate 251; is. mounted a. lleneasting.. 2.3. ofthe same. length and width as base plate.. 2.1 but having cut-.oit outer, corners 29 and a centrally disposed,- cutout 39. of a. size CQIIeSDonding.- substantiallyr with that oftheJ pan to, be.` formed; SaidE llerA casting 28. serves. as a. .f Olmdation. for, and has.. mounted; upon it. the 1092er blanking die3 31a whose. inner.- edge 32 corresponds.. in. shapetdblank. 2t. For easeof manufacture, ysaid lowerblanking die.3 if may-be made up` of, separate sections., the. drawing. here, showing tw@ each ci; long sidev sections.V 33 and; short side sections 33a and four corner sections 3.1i. The, inner.- perphery. or these taken, together, Q1111.1.9.b1ankr,1g edge. Said. lower. blanking. die 3th mates.. with and. receives, 'oneA uppery blanking punch. 3.5;, which is. adapted form mountna to and beneath the Outer ram. of:y such` doublefacting press, Along theinner edge ofiv punch: is angefiotmina Ghamferor groove, 36..

I eferring again to Figures. 6.and18i mounted @9011. base.. plate. 2:1: and spaced within the mier 6,8.Si-1i1t--Zarzis.l bottom. die, segment. 3 1 whose. shape CQ1Z1`DQDQ 11h@ generally rectangular, curved- QQiIler bQiOm of: the. pan te be manufactured. diegene '011.8 Straight.: pcrticns off the sides. of 9950121 die-Segment 35.1 anni servite toL space it 111.18.12 Gestes are; upwardly-extending. gi. I'Qllnfsedgd; blades. 3.3.,y which. are @dan .a tolera-.the Sides angie. mate with cnamfet 36; te. orm the. flanges 215; 'ofthe pail. Betvv nlthe, adjacentblades Miara thelccncavly mi we; Queue eine" da amne' 'sa' "iv-1.1 di ment 31'- eaehe notehed a.. 65 each @Premi-Wrme, gui@ eiffQQ. die Segments 3.9-1.. 'Reese notches S5 `retest Seen in Rigs, e and 7,. Each of these die Segmente 3.9i asentar/.n detail ia meer@ '1., este en. a autres@ 411 inserted 1arte-eating' retenes 4.1.. '42.,

4 in the corner die segments 39 and base plate 21, respectively. Within the outer' surface of each of said corner dies 39 is cut a vertical guide groove or keyway 43, Whose upper and lower ends serve as abutments 44. Removable bolts 45 are tapped through filler casting 28 at cut-off` corners 29 to engage said guide groove 43. rihese bolts 45 permitI vertical `irifcgvenientv4 of" the corner dies 39 within the limits permitted by guide groove abutments 44. From the drawing it is apparent that at the lower limit of their travel, theI said outside, corner die `segments 3S will be retracted to form along with bottom 31 and bladesl 38 a temale die for the pan as a whole.

l the upper limit of their travel said outside corner die Asegments 99 are at such height above thejblades; 3,6) (Eig. 8) that they function to form the tucks 24 in the pan corners in advance of the formation of the pan sides by blades 38, as hereinafter described.

Bottom segmentt and base plate 2-1; are penetrated by a plurality. of; bores 13,6 thrcugril which protrude push-.Out pins, 4.1 mounted on a pin plate 48. Said pin plate has al central borei 528 which adapts it OI? Vertical movement along md 5.9,. `Said rod 5i); is aixed. below the base plate 21 and supports cmpression. spring et which rests on collar 52. and nutv 531 mounted on, rod 5.0. The spring 5l yieldably supports plate 4.8y for the pins`v 451.

Referring.Y to the upper die elements, amxedf beneath the main or. inner ram of the. dowblacting press` (not shown), is the upper central mounting casting plietratedqby. bores having dametrallwenlarsed upper portions 5,6. The junctures off said, upperl enlarged bore portions 543,y with. bores 55` constitutel shoulder steps` 5;'1. Adapted forrecillrotal,v movement. within bores 55 are stop bolts 58 whoseheads are adapted to engage.shoulder-StOpS` 51;. The lower. threaded portions 0f. belts. 5.8 are xediy. mounted a fleeting upper male die. 6B so'. that. the die. may besuspenciedf by them,- It will;- be seen. that the shoulder stops 51 serve to limit the amount. by which. male die. 50, mail be separated from the mounting. Casilina` 54.... In. the matedrecesses. el, 62, bored in, mounting casting7 5d and; male die 69 respectively.-

ccmpression springs.u 63 Which sie@ auch sepaation, until: meintcreeis overcome by bottomine male. die 6.0.

'I ne fo-llcwing is` a. descriltiouV of thei process of pan-folding as it is carried out with` thepartulaldies illustrated; As, the double-acting presa is. engaged', its: cuter ram. lowers in, ad.i vente of its ramicausine the blankinapunch (Figw.) tQuilhe blank 2.1i. shownY Eigurel. Seid. blanks 2l; is theleafftet Supported by push- Qutipin 41. and; srressed. dnwnwardf against sain Pins-'by male die 60;.` Assaiddie stgvlowers, the Said pins 41 are. depressed. and ein plate. is, is gradually muerta impressing the. springA 5| against. the Collet' 52. When; mallei die 6.0: approahes the raised terrier. die 'seamen-ts. es. as S..1.QWnf.1;Fg1u1e-,9 1316.55151- QQrner; die segments 3.9 fue me. corner 2.2 urbani. 2.1. upwardabaut said male; diel 5i),- whiclr gradually, depressies. said 3.951.162 dries Sllenl' @firegaintg their ccmpres- Smilies. 49.. As said) :nales die. et, continues its descent, blades. 33. formi thepan..sides. upward. When. said:` male. dieA` (il)4 bottoms` against the bottom die segment 31, as in Figure 10., the corner die.seguier-its.A 39e areush. with said'. bottom die segment.- 31.; and.y push-.out pins 411: are fully retracted. Compression springs 63, holding die.x 60.1. anar-.12.; frommouatme @Stine `'are ..5 then still extended. It is at this stage that the pan sides 23 are iiattened and the tucks 24, liankw ing corners 22 and extending upward and outward from the lower portions thereof are tightly creased.

The pan then takes the form shown in Figure 3, except that the corner tucks are closed. Thereafter, as upper casting 54 and blanking punch 35 continue to descend together, compression springs 63 are compressed, permitting male die 50 to remain motionless for the time. Thus, the pan anges 25 are formed by the mating of chamfer 36 in the punch 35 with the upper edges of blades 38. Inasmuch as blades 33 extend the full distance between the corner die segments 39, the anging operation just described also turns outward and somewhat downward the upper portions of tucks 24, which, when so hanged, constitute plicas 26. The pan is then completed and is ejected by the pins 4'! as the upper die portions raise. From inspection of Figures 4 and 5, the manner in which said plicas 26 strengthen the pan and prevent its unfolding is readily observed.

It is apparent that the steps of my process can be carried out with somewhat different dies and presses, whether single or double-acting. The embodiment illustrated is a convenient one to show the progression of operations but my invention is not limited to the use of the die specifically' illustrated.

Nor is my process dependent upon any specic dimensions or proportions of the foil, blanks from which the pans are formed. On inspection of Figure 3, it is apparent that the outer fold of each o1' tucks 24 (i. e., the fold visible on the outer side of the pan) Will be of greater length than the inner fold. Such greater length is due to the general fan shape of corners 22 together with the manner of folding. As shown in Fig. 5 the outer fold line is substantially perpendicular to the base line of the pan and gives to the sides 23 greater height than the adjacent portions of the corners 22. However, it is obvious that the outer fold line may be at an angle to the base line of the pan other than perpendicular and still produce the greater height in the sides 23 over the adjacent portions of the corners 22. As shown in Figure 5, the point at which the sides 23 are bent outward to form flanges 25 is immediately above the upper margins of corners 22. Stated differently, the available width of flange 25 depends upon such difference in height as is provided between the walls 23 and the corner 22. Such difference in height also makes possible the plica 26,

which results from the outward flanging of the portion of the tucked material extending above the height of the adjacent portion of corner 22.

Likewise, the order of operations might be changed so as to fold the pan sides before unfolding the corner portions outward thereof, completing the pan by anging side margins, including tucked portions flanking the corners, in the manner hereinbefore described.

Other changes and modioations in the form, construction, arrangement and combination ol the several portions of the pan, and in the steps comprising the method of its manufacture, may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention what I now claim and desired to secure by Letters Patent is- 1. The method of making a bakery goods baking and packaging pan from a sheet of foil material having in its at condition a rectangular shape with fan-shaped rounded corners, which method includes the steps of punching a pan blank in flat condition and to the shape specied, lirst initiating the forming oi the corners, from the plane of the blank to start inwardly directed folds along regulated lines at each side of the corners, simultaneously bending up the sides of the pan blank and completing the forming of the corners with the folds at each side against the inner surfaces of the pan sides, and stiiening the pan sides between the corners and securing the corner folds by outwardly turning the margins of the pan sides to form flanges extending into and catching the corner folds to lock the folds at each sido of each corner.

l2. The method of making a baking and packaging pan from a dat sheet of metallic foil material which includes the steps of forming a pan blank of rectangular outline with rounded corners between blanking dies, punching the pan blank into a forming die and, while still in the forming die, first moving the blank and corner forming dies relatively for initiating the forming of rounded corners by starting a pair of well defined creases at each side of the corners to start inwardly turned folds from the plane of the blank, relatively moving the forming and corner dies for substantially simultaneously closing the corner folds along the pairs of creases with the folds at each side against the inner surface of the pan sides, and stiffening the pan sides between the corners by forming the pan sides with outwardly rolled flanges extending into and catching the corner folds to lock the folds at veach side of each corner, and ejecting the completely formed and stiffened pan from the forming die.

3. The method of making a pan from a flat sheet of metallic foil material comprising punching out a pan blank in nat condition to a rectangular shape having arcuately flattened corners, initiating the pan forming by starting a pair of fold creases fanning outwardly from each side of the corners of the blank to denne each pan corner wall between two folds, continuing the pan forming by bending the corners and side walls out of the plane of the blank and simultaneously closing the corner folds to form tucks at the inside of the side walls with the folds at each side against the inner surfaces of the pan sides, and completing the pan forming by concurrently outwardly rolling the lip portions of the side walls between the corners to stiffen the side Walls and carrying the side wall lip rolling operation into the corner tucks to lock the corner folds in the rolled lip portions of the side walls.

WILLIAM G. SWAINE.

References Cited in the le oi this patent UNITED STATES PATENTS Number Name Date 820,976 Katzinger May 22, 1906 927,537 Hothersall July 13, 1909 1,304,740 Carpenter May 27, 1919 1,403,642 Sauvage et al Jan. 17, 1922 1,438,698 Debs Dec. 12, 1922 2,358,457 Jackson Sept. 17, 1922 2,125,793 Linderman Aug. 2, 1938 2,216,147 Ward Oct. 1, 1940 FOREIGN PATENTS Number Country Date 560,356 Great Britain Mar. 31, 1944 

